The invenlion relates to sound synthesizer and sound effects generator circuits, and particularly to single chip implemented circuits compatible with discrete logic or LSI processors for generating sound effects and/or musical notes when used independently or with external audio sources.
An object of this invention is to provide a sound synthesizer circuit on a single LSI chip which is compatible with NMOS technology.
A second object of this invention is to provide such a circuit which is capable of generation of 3 separate tones with a frequency of 0 to 4 KHz.
A third object of this invention is to provide such a circuit which is capable of generating 4 waveforms from each of the 3 separate tone generators/oscillators.
Another object of this invention is to provide such a circuit with 3 amplitude modulators with a range of 48 dB.
Another object of this invention is to provide such a circuit with 3 envelope generators capable of exponential responses for "attack rate" of 2 ms to 8 s, for "decay rate" of 6 ms. to 24 s, for "sustain level" of 0 to peak volume, and for "release rate" of 6 ms to 24 s.
A further object of this invention is to provide such a circuit with ring modulation, oscillator synchronization and programmable filter capabilities.